Kuumapurkistus

Kuumapurkistus, also known as hot filling, is a food preservation technique used to extend the shelf life of liquid or semi-liquid food products. This method involves filling containers, such as glass jars or bottles, with a product that has been heated to a specific high temperature, typically above 85 degrees Celsius (185 degrees Fahrenheit). The hot product then heats the container and its lid, creating a vacuum seal as it cools.

The high temperature of the product during filling is crucial for inactivating microorganisms, including bacteria, yeasts, and molds, that could cause spoilage. This thermal processing effectively sterilizes the product and the headspace within the container. The subsequent cooling process causes the air inside the container to contract, drawing the lid tightly against the rim and forming a hermetic seal. This vacuum seal prevents the re-entry of microorganisms and oxygen, further contributing to the product's preservation.

Kuumapurkistus is commonly employed for a variety of food products, including fruit juices, jams, sauces, pickles, and some dairy-based beverages. It is a cost-effective method that does not require specialized equipment beyond standard filling and sealing machinery. The effectiveness of kuumapurkistus relies on maintaining the correct product temperature and ensuring a proper seal is achieved. Factors such as product acidity and water activity also play a role in the overall success of this preservation technique.